y."

I have left the passage about the white and red stripe, because it will
be useful to us presently; all that I wish to insist upon here is the
showing of the local color (pea green) of the water in the spaces which
were occupied by dark reflections, and the unaltered color of the bright
ones.

Sec. 8. Water takes no shadow.

Third: Clear water takes no shadow, and that for two reasons; A perfect
surface of speculum metal takes no shadow, (this the reader may
instantly demonstrate for himself,) and a perfectly transparent body as
air takes no shadow; hence water, whether transparent or reflective,
takes no shadow.

But shadows, or the forms of them, appear on water frequently and
sharply: it is necessary carefully to explain the causes of these, as
they are one of the most eminent sources of error in water painting.

First: Water in shade is much more reflective than water in sunlight.
Under sunlight the local color of the water is commonly vigorous and
active, and forcibly affects, as we have seen, all the dark reflections,
commonly diminishing their depth. Under shade, the reflective power is
in a high degree increased,[61] and it will be found most frequently
that the forms of shadows are expressed on the surface of water, not by
actual shade, but by more genuine reflection of objects above. This is
another most important and valuable circumstance, and we owe to it some
phenomena of the highest beauty.

A very muddy river, as the Arno for instance at Florence, is seen during
sunshine of its own yellow color, rendering all reflections discolored
and feeble. At twilight it recovers its reflective power to the fullest
extent, and the mountains of Carrara are seen reflected in it as clearly
as if it were a crystalline lake. The Mediterranean, whose determined
blue yields to hardly any modifying color in daytime, receives at
evening the image of its rocky shores. On our own seas, seeming shadows
are seen constantly cast in purple and blue, upon pale green. These are
no shadows, but the pure reflection of dark or blue sky above, seen in
the shadowed space, refused by the local color of the sea in the
sunlighted spaces, and turned more or less purple by the opposition of
the vivid green.

Sec. 9. Modification of dark reflections by shadow.

We have seen, however, above, that the local color of water, while it
comparatively refuses dark reflections, accepts bright ones without
deadening them. Hence when a sh